Processes for preparing oxygenates and catalysts therefor

ABSTRACT

This invention relates in part to a processes and catalysts for the conversion of a feedstock comprising carbon monoxide and hydrogen to a product stream comprising at least one of an ester, acid, acid anhydride and mixtures thereof. This invention also relates in part to processes and catalysts for converting an alcohol, ether and/or ether alcohol feedstock to oxygenated products, e.g., esters, acids, acid anhydrides and mixtures thereof. The processes and catalysts are especially suitable for the production of acetic acid and methyl acetate from a synthesis gas feedstock or from an alcohol, ether or ether alcohol feedstock.

This application is a continuation-in-part of U.S. patent applicationSer. No. 09/192,134, filed Nov. 13, 1998 now abandoned which is acontinuation-in-part of U.S. patent application Ser. No. 09/015,240,filed Jan. 29, 1998 now abandoned.

BRIEF SUMMARY OF THE INVENTION

1. Technical Field

This invention relates in part to processes for converting carbonmonoxide- and hydrogen-containing feedstocks, e.g., synthesis gas, tooxygenated products, e.g., esters, acids, acid anhydrides and mixturesthereof, and to catalysts for said processes. This invention alsorelates in part to processes for converting an alcohol, ether and/orether alcohol feedstock to oxygenated products, e.g., esters, acids,acid anhydrides and mixtures thereof, and to catalysts for saidprocesses.

2. Background of the Invention

It is known that carboxylic esters, acids, anhydrides and mixturesthereof can be prepared from feedstock comprising carbon monoxide andhydrogen gases by first forming an alcohol, such as methanol, and thecorresponding ether (e.g., dimethyl ether), according to the theoreticalreaction:

    2CO+4H.sub.2 =2CH.sub.3 OH(CH.sub.3).sub.2 O+H.sub.2 O

in the presence of a known alcohol conversion catalyst, and thenseparately converting the alcohol and/or ether in the presence of aknown carbonylation catalyst into esters, acids, anhydrides and mixturesthereof containing one carbon atom more than the starting alcohol andether, for example (theoretically):

    CH.sub.3 OH+CO=CH.sub.3 COOH                               or

    (CH.sub.3).sub.2 O+2CO+H.sub.2 O=2CH.sub.3 COOH            or

    CH.sub.3 OH+(CH.sub.3).sub.2 O+3CO+H.sub.2 O=3CH.sub.3 COOH

Known two step catalytic processes for producing oxygenates aredescribed in U.S. Pat. Nos. 5,189,203 and 5,286,900. In each of theprocesses described in these patents, the alcohol conversion from carbonmonoxide and hydrogen is carried out in a first reaction zone whereinthe alcohol, and optionally the corresponding ether, are refined to aproduct stream and the product stream is then passed from the firstreaction zone to a second reaction zone wherein the alcohol and etherare converted by a carbonylation reaction to ester, acid, anhydride ormixtures thereof. As disclosed, the useful temperature and pressureranges for carrying out the separate reactions are different.Specifically, the alcohol synthesis reactor temperatures and pressuresare selected from the ranges of from about 150° C. to about 400° C. andfrom about 70 to 3000 psig, respectively, whereas the carbonylationreactor temperatures and pressures are selected from the ranges of fromabout 100° C. to about 500° C. and about 15 to 12,000 psig,respectively.

It has been disclosed that oxygenates can be produced from a synthesisgas from rhodium catalysts. JA 62/148437 and JA 62/148438 disclose thesimultaneous production of acetic acid, acetaldehyde and ethanol from asynthesis gas reacted in the presence of a rhodium catalyst pretreatedwith sulfur-containing compounds. JA 61/178933 discloses producingoxygenates from a synthesis gas wherein the reaction is carried out inthe presence of a rhodium catalyst provided with an accelerator metalsuch as scandium, iridium or an alkali earth metal. JA01/294643discloses the production of oxygenated compounds such as acetic acid inwhich a synthesis gas is reacted in the presence of a rhodium catalyston a silica substrate.

The cited prior art processes for producing oxygenates from a synthesisgas have taken one of two routes: a first route wherein two separatereaction zones are used--a first reaction zone to produce the alcohol,followed by separation and purification, and a second reaction zone toeffectuate the carbonylation reaction to produce oxygenates, wherein thetemperatures and pressures are selected from different ranges; and, asecond route wherein a rhodium catalyst, contained on a substrate ortreated with a specific compound (such as sulfur-containing compounds)or enhanced by an accelerator, is used to produce oxygenates and/ormixtures thereof along with aldehydes and alcohols. The first route isinefficient and capital intensive, requiring separate reaction zones,alcohol purification and complex equipment. The second route suffersfrom poor selectivity, resulting in a broad range of oxygenatedproducts, because one catalytic component is being used to catalyze bothreactions.

Known catalytic carbonylation processes for producing oxygenates aredescribed in U.S. Pat. Nos. 5,218,140 and 5,330,955. Such processesinvolve the carbonylation of one or more alcohols, ethers and etheralcohols to esters and carboxylic acids. The processes are carried outin the vapor state over a solid catalyst comprising a polyoxometalateanion in which the metal is at least one taken from Groups 5 and 6 (suchas molybdenum, tungsten, vanadium, niobium, chromium and tantalum)complexed with at least one Group 8, 9 or 10 cation (such as Fe, Ru, Os,Co, Rh, Ir, Ni, Pd and Pt).

Currently, commercial processes for the production of acetic acid frommethanol and carbon monoxide employ iodide promoters which are essentialto obtain an acceptable level of catalyst activity. Iodide promoters arehighly corrosive, requiring the use of exotic metals in the constructionof the reaction vessels and expensive processing equipment (e.g.,separation and refining equipment) to recover the homogeneous promoterfrom the product stream.

The oxygenates industry, particularly the acetic acid industry, wouldbenefit significantly from a process that would simplify and/oreliminate complex, expensive equipment while simultaneously enablingmore control over reaction rates and product selectivity. A solutionenabling these advantages would provide a highly desirable industrialadvance. Improved carbonylation catalysts for making oxygenates withrespect to catalyst stability and carbonylation activity and selectivitywould also be a highly desirable industrial advance.

DISCLOSURE OF THE INVENTION

This invention relates in part to a process for converting a feedstockcomprising carbon monoxide and hydrogen to a product stream comprisingat least one of an ester, acid, acid anhydride and mixtures thereofwhich comprises reacting the carbon monoxide and hydrogen in thepresence of a catalyst comprising an alcohol synthesis catalyticcomponent and an alcohol carbonylation catalytic component, thecomposition of the components being different from one another, underconditions of temperature and pressure sufficient to produce saidproduct stream. This process is preferably a gas or vapor phase reactionof synthesis gas to produce oxygenates therefrom, and is especiallyadvantageous for the production of acetic acid and/or methyl acetateutilizing a single reaction vessel.

This invention also relates in part to a process for converting afeedstock comprising carbon monoxide and hydrogen to a product streamcomprising at least one of an ester, acid, acid anhydride and mixturesthereof which comprises (a) reacting the carbon monoxide and hydrogen inthe presence of a catalyst under conditions of temperature and pressuresufficient to produce at least one of an alcohol, ether, ether alcoholand mixtures thereof and (b) reacting carbon monoxide and said at leastone of an alcohol, ether, ether alcohol and mixtures thereof in thepresence of a catalyst comprising a solid super acid, clay, zeolite ormolecular sieve under conditions of temperature and pressure sufficientto produce said product stream. This process is preferably a gas orvapor phase reaction, and is especially advantageous for the productionof acetic acid and/or methyl acetate utilizing separate reaction vesselsfor steps (a) and (b).

This invention further relates in part to a process for converting afeedstock comprising at least one of an alcohol, ether, ether alcoholand mixtures thereof to a product stream comprising at least one of anester, acid, acid anhydride and mixtures thereof by reacting carbonmonoxide and said at least one of an alcohol, ether, ether alcohol andmixtures thereof in the presence of a catalyst comprising a solid superacid, clay, zeolite or molecular sieve under conditions of temperatureand pressure sufficient to produce said product stream. This process ispreferably a gas or vapor phase reaction, and is especially advantageousfor the production of acetic acid and/or methyl acetate utilizing one ormore reaction vessels.

This invention yet further relates in part to a multicomponent catalystcomprising (a) a first component capable of catalyzing a reaction ofcarbon monoxide and hydrogen to produce at least one of an alcohol,ether, ether alcohol and mixtures thereof and, (b) a second componenthaving a composition different from that of the first component andcapable of catalyzing a reaction of carbon monoxide and said at leastone alcohol, ether, ether alcohol and mixtures thereof produced in thepresence of the first component to produce at least one of an ester,acid, acid anhydride and mixtures thereof.

This invention also relates in part to a solid catalyst for thecarbonylation of a feedstock comprising at least one of an alcohol,ether, ether alcohol and mixtures thereof to a product stream comprisingat least one of an ester, acid, acid anhydride and mixtures thereof, byreaction thereof in the vapor state, said catalyst selected from a solidsuper acid, clay, zeolite or molecular sieve.

The processes and catalysts of this invention are particularly unique inthat they enable the production of oxygenates from carbon monoxide- andhydrogen-containing feedstocks or alcohol, ether or ether alcoholfeedstocks in one or more reactors and in which no halides are requiredin the liquid or vapor phases of the feedstock streams and/or recyclestreams of the processes, thus providing substantial economic benefitsin the design of equipment to carry out the processes. Moreover, themulticomponent catalysts of this invention enable substantial controlover the composition of the reaction product simply by varying thecomposition of one component of the catalyst and/or its concentrationrelative to the other component. Further, the processes and catalysts ofthis invention enable the production of oxygenates under one or moresets of reaction conditions. The carbonylation catalysts of thisinvention provide improved catalyst stability and improved carbonylationactivity and selectivity as described herein. In a preferred embodiment,the alcohol producing reaction, i.e., step (a) above, and carbonylationreaction, i.e., step (b) above, can be carried out in separate reactorsand each reactor can be operated at different reaction conditions. Theproduct stream exiting the alcohol synthesis reactor can be fed directlyinto the carbonylation reactor.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic representation of a one-reactor process flowdiagram to make acetic acid from a feedstock gaseous mixture comprisingcarbon monoxide and hydrogen gases prepared from a hydrocarbon feed to a"synthesis gas" or "syn gas" generator.

FIG. 2 is a schematic representation of a two-reactor process flowdiagram to make acetic acid from a feedstock gaseous mixture comprisingcarbon monoxide and hydrogen gases prepared from a hydrocarbon feed to a"synthesis gas" or "syn gas" generator.

DETAILED DESCRIPTION

According to one embodiment of this invention, a feedstock comprisingcarbon monoxide and hydrogen is converted to a product stream comprisingat least one of an ester, acid, acid anhydride and mixtures thereof byreacting the carbon monoxide and hydrogen, in the presence of acatalyst, to convert the same to the product stream, wherein thecatalyst comprises an alcohol synthesis catalytic component and analcohol carbonylation catalytic component. In particular, a gaseousfeedstock comprising carbon monoxide and hydrogen gases is converted tothe product stream in a vapor phase, controlled temperature andpressure, reaction in the presence of a solid catalyst comprising ametal based alcohol synthesis catalytic component and an alcoholcarbonylation catalytic component.

More particularly, the gas feedstock is converted to the product streamin the presence of a solid catalyst comprising a metal based alcoholsynthesis catalytic component and a heterogeneous alcohol carbonylationcatalytic component. Preferably, such processes yield a product streamcomprising at least one of acetic acid, methyl ester, acetic anhydrideand mixtures thereof and is carried out in the presence of a solidcatalyst system comprising a metal-based alcohol synthesis catalyticcomponent and a solid super acid alcohol carbonylation catalyticcomponent. More preferably, a synthesis gas feedstock is convertedsubstantially to acetic acid in a vapor phase, catalyzed, temperatureand pressure controlled reaction wherein the catalyst is a solidcatalyst consisting essentially of a metal-based alcohol synthesiscatalytic component and a solid super acid impregnated with a Group 7,8, 9, 10 and/or 11 metal.

This embodiment is simple and unique. The processes to produce theproduct stream are carried out in a single reaction zone in the presenceof a multicomponent catalyst whose composition can be varied by changingthe catalytic components so as to control the rate and selectivity ofthe first and/or second reactions, thereby effectively controlling thecomposition of the product stream and the rate of production of thestream constituents. In a preferred embodiment of such processes, themulticomponent catalyst is a solid catalyst consisting essentially of ametal-based alcohol synthesis catalytic component and a heterogeneousalcohol carbonylation component. The unique catalyst enables highlyselective and rate controllable processes which can be carried out undera singular set of reaction condition temperatures and pressures. Themulticomponent catalyst may comprise one or more catalyst beds in asingle reaction vessel, e.g., a dual bed catalyst which comprises onebed containing the alcohol synthesis catalytic component and anotherseparate bed containing the alcohol carbonylation catalytic component,or a single bed catalyst mixture, e.g., a mixture of the alcoholsynthesis catalytic component and the alcohol carbonylation catalyticcomponent.

It has been discovered that hydrogen or a feedstock containing hydrogen,e.g., synthesis gas, has an unexpected stabilizing effect on theheterogeneous alcohol carbonylation catalytic component of the catalystas compared to reactions in which only methanol and carbon monoxide arepresent in the system as described more fully below. This unexpectedeffect is especially valuable for the production of acetic acid.

In another embodiment, this invention is directed to processes andcatalysts for converting a feedstock comprising carbon monoxide andhydrogen to a product stream comprising at least one of an ester, acid,anhydride and mixtures thereof, which comprises (a) reacting the carbonmonoxide and hydrogen in the presence of a catalyst under conditions oftemperature and pressure sufficient to produce at least one of analcohol, ether, ether alcohol and mixtures thereof and (b) reactingcarbon monoxide and said at least one of an alcohol, ether, etheralcohol and mixtures thereof in the presence of a catalyst comprising asolid super acid, clay, zeolite or molecular sieve and under conditionsof temperature and pressure sufficient to produce said product stream.In this embodiment, the processes are preferably carried out in twolinked reaction vessels with the first reaction vessel containing thealcohol synthesis catalyst and the second reaction vessel containing thecarbonylation catalyst.

As with the multicomponent catalyst above, it has been discovered thathydrogen or a feedstock containing hydrogen, e.g., synthesis gas, has anunexpected stabilizing effect on the carbonylation catalyst employed instep (b) above as compared to reactions in which only methanol andcarbon monoxide are present in the system as described more fully below.This unexpected effect is especially valuable for the production ofacetic acid.

An illustrative overall reaction of the processes of this invention in asingle reaction zone can be represented as follows: ##STR1## wherein Ris an alkyl group from 1 to about 12 carbon atoms, and R' is hydrogen oran alkyl group from 1 to about 12 carbon atoms, and wherein m is aninteger of 1 or 2, n is 0 when m is 2, and n is 1 when m is 1, x and yare the stoichiometric coefficients for a particular reaction, and z isone less than the number of carbon atoms of R.

Another illustrative overall reaction of the processes of this inventionin separate reaction zones can be represented as follows: ##STR2##wherein R is an alkyl group from 1 to about 12 carbon atoms, and R' ishydrogen or an alkyl group from 1 to about 12 carbon atoms, and whereinm is an integer of 1 or 2, n is 0 when m is 2, and n is 1 when m is 1, xand y are the stoichiometric coefficients for a particular reaction, andz is one less than the number of carbon atoms of R.

Processes for reforming hydrocarbons to produce synthesis gas are wellknown. Each has its advantages and disadvantages and the choice of usinga particular reforming process is dictated by economic and availablefeed stream considerations, as well as by the desired mole ratio of H₂:CO in the feedstock resulting from the reforming reaction. Steamreforming typically produces a hydrogen to carbon monoxide mole ratiogreater than about 2.5:1. Partial oxidation reforming can typicallyproduce smaller hydrogen to carbon monoxide mole ratios. Partialoxidation reforming of alkane is a controlled combustion reaction inwhich a feed stream of alkane hydrocarbon, such as methane, and oxygenis introduced into a combustion chamber. The combustion conditions arecontrolled to selectively make the desired hydrogen-carbon monoxideratio in the feedstock. Steam reforming and partial oxidation ofhydrocarbons are well known processes and are described, for example, inKirk-Othmer, Encyclopedia of Chemical Technology, Fourth Edition, 1996,the pertinent portions of which are incorporated herein by reference.

Any hydrocarbon-containing feed stream that can be converted into afeedstock comprising carbon monoxide and hydrogen, most preferably asynthesis gas (or "syn gas"), is useful in the processes of theinvention. The ratio of hydrogen to carbon monoxide in the reaction zoneis in the range of about 50:1 to 1:50, preferably in the range of about20:1 to 1:20, more preferably in the range of about 10:1 to 1:10. Usefulfeed streams include natural gas (mainly methane, but natural gascomposition can vary depending on location and source), naphtha,refinery off-gas, LPG, gas oil, vacuum residuals, shale oils, asphalts,various types of fuel oils, and hydrocarbon containing process recyclestreams. In a preferred embodiment, methanol can be converted into feedcomponents comprising carbon monoxide and hydrogen, e.g., synthesis gas.Further, hydrogen may be formed in situ, for example, by water-gasshift.

Feedstocks comprising carbon monoxide and hydrogen, e.g., synthesis gas,may undergo purification prior to being fed to any reaction zones. Foruse in the processes of this invention, the synthesis gas should beessentially free of catalyst poisons and inhibitors such as hydrogensulfide, carbonyl sulfide, metal carbonyls, e.g., iron carbonyl andnickel carbonyl, ammonia, basic organic compounds, e.g., methyl amineand ethyl amine, and generally any compounds that will neutralize anacid. Synthesis gas purification may be carried out by processes knownin the art. See, for example, Weissermel, K. and Arpe H.-J., IndustrialOrganic Chemistry, Second, Revised and Extended Edition, 1993, pp.19-21.

The particular reaction conditions for both the single reactor andseparate reactor embodiments described below are not narrowly criticaland can be any effective reaction conditions sufficient to produce atleast one of an ester, acid, acid anhydride and mixtures thereof. Theexact reaction conditions will be governed by the best compromisebetween achieving high catalyst selectivity, activity, lifetime and easeof operability, as well as the intrinsic reactivity of the startingmaterials in question and the stability of the starting materials andthe desired reaction product to the reaction conditions.

In one embodiment of this invention, feedstock comprising the desiredmolar ratio of H₂ :CO is fed to a single reactor at a controlled rateand the reaction is carried out in a reaction zone under controlledconditions of temperature and pressure in the presence of a catalyst toconvert the feedstock into one or more oxygenates. The temperature inthe reaction zone is selected from the range of from about 100° C. toabout 500° C., preferably a temperature in the range of from about 150°C. to about 400° C., with an especially preferred temperature in therange of from about 175° C. to about 375° C. The gas hourly spacevelocity (GHSV) of the feedstock (liters of feedstock/hr/liter ofcatalyst) passing through the reaction zone can vary significantly,depending upon a variety of factors such as, for example, reactionconditions, composition of the feedstock and quantity and type ofcatalyst being used. The GHSV can be maintained at any rate in the rangeof from about 1 to about 30,000 hr⁻¹, or more, preferably will bemaintained at a rate of at least about 500 hr⁻¹, and more preferablywill be maintained at a rate of at least 1,000 hr⁻¹.

The pressure in the single reaction zone may be selected from the rangeof from about 1 to about 10,000 psig, preferably a pressure in the rangeof from about 50 to about 5,000 psig, with an especially preferredpressure in the range of from about 500 to about 3,000 psig. Thehydrogen and carbon monoxide partial pressures should be sufficient toenable the production of one or more oxygenates. Additionally, thehydrogen partial pressure should be sufficient to impart stabilizationto the carbonylation catalytic component. Illustrative hydrogen partialpressures may range, for example, from about 0.1 psig or less to about9000 psig or greater, or from about 0.1 psig or less to about 4500 psigor greater, or from about 0.1 psig or less to about 2700 psig orgreater. Illustrative carbon monoxide partial pressures may range, forexample, from about 0.1 psig or less to about 9000 psig or greater, orfrom about 0.1 psig or less to about 4500 psig or greater, or from about0.1 psig or less to about 2700 psig or greater. Hydrogen and carbonmonoxide may be fed separately to the single reactor or in combination,e.g., synthesis gas.

In another embodiment of this invention, when the alcohol producingreaction and carbonylation reaction are carried out in separate reactionvessels, a feedstock comprising the desired molar ratio of H₂ :CO is fedto the alcohol producing reactor at a controlled rate and the reactionis carried out in a reaction zone under controlled conditions oftemperature and pressure in the presence of a catalyst to convert thefeedstock into one or more alcohols, ethers, ether alcohols and mixturesthereof. Such reactions may be carried out by conventional methods knownin the art. See, for example, U.S. Pat. Nos. 5,189,203 and 5,286,900.The product stream exiting the alcohol reactor may then be fed to thecarbonylation reactor at a controlled rate and the reaction is carriedout in a reaction zone under controlled conditions of temperature andpressure in the presence of a catalyst as defined herein to convert thefeedstock into one or more oxygenates.

The temperature in the carbonylation reaction zone is selected from therange of from about 100° C. to about 500° C., preferably a temperaturein the range of from about 150° C. to about 400° C., with an especiallypreferred temperature in the range of from about 175° C. to about 375°C. The gas hourly space velocity (GHSV) of the feedstock (liters offeedstock/hr/liter of catalyst) passing through the carbonylationreaction zone can vary significantly, depending upon a variety offactors such as, for example, reaction conditions, composition of thefeedstock and quantity and type of catalyst being used. The GHSV can bemaintained at any rate in the range of from about 1 to about 30,000 hr⁻¹or more, preferably will be maintained at a rate of at least about 500hr⁻¹, and more preferably will be maintained at a rate of at least 1,000hr⁻¹. Likewise, the liquid hourly space velocity (LHSV) of the feedstockpassing through the carbonylation reaction zone can vary significantly,depending upon a variety of factors such as, for example, reactionconditions, composition of the feedstock and quantity and type ofcatalyst being used. The LHSV to the reactor when the feed is vaporizedprior to entering or within the reactor may range from about 0.001 toabout 100 hr⁻¹, preferably from about 0.01 to about 10 hr⁻¹. The GHSVand LHSV accommodate the amount of alcohol, ether, ether alcohol andmixtures thereof fed to the carbonylation reactor.

The pressure in the carbonylation reaction zone may be selected from therange of from about 1 to about 10,000 psig, preferably a pressure in therange of from about 50 to about 5,000 psig, with an especially preferredpressure in the range of from about 500 to about 3,000 psig. The carbonmonoxide partial pressure should be sufficient to permit the reactionwith an alcohol, ether, ether alcohol or mixtures thereof to produce oneor more oxygenates. The hydrogen partial pressure should be sufficientto impart stabilization to the carbonylation catalyst. Illustrativehydrogen partial pressures may range, for example, from about 0.1 psigor less to about 9000 psig or greater, or from about 0.1 psig or less toabout 4500 psig or greater, or from about 0.1 psig or less to about 2700psig or greater. Illustrative carbon monoxide partial pressures mayrange, for example, from about 0.1 psig or less to about 9000 psig orgreater, or from about 0.1 psig or less to about 4500 psig or greater,or from about 0.1 psig or less to about 2700 psig or greater. Hydrogenand/or carbon monoxide may be fed separately to the carbonylationreactor or in combination, e.g., as synthesis gas or as part of a feedstream from a separate reactor as described herein. In a preferredembodiment, methanol can be converted into feed components comprisingcarbon monoxide and hydrogen, e.g., synthesis gas.

For purposes of this invention, GHSV is gas hourly space velocity whichis the rate of gas flow over the catalyst. It is determined by dividingthe volume of gas (at 25° C. and 1 atmosphere) which passes over thecatalyst in one hour by the volume of the catalyst. LHSV is liquidhourly space velocity which is the rate that the liquid organicsubstrate is fed to the carbonylation reactor. It is determined bydividing the liquid volume pumped in one hour by the volume of catalyst.

The carbonylation reaction can be carried out by passing the substrateto be carbonylated and carbon monoxide and optionally hydrogen over thecatalyst as a vapor phase reaction or as a liquid phase reaction, e.g.,slurry reaction. The substrate comprising an alcohol, ether, etheralcohol or mixtures thereof can be formed in situ by feeding synthesisgas to an appropriate catalyst that is coupled to the carbonylationcatalyst either in the same or different reactors. If desired, suchsubstrates, e.g., methanol, and/or synthesis gas can be obtained from adifferent source and fed directly to the carbonylation catalyst.

The alcohol synthesis catalyst or alcohol synthesis catalytic componentis selected from either of two groups: a first group which includes: (a)alkali and/or metal promoted MoS₂ -based materials, (b) Group 7, 8, 9,10 and/or 11 metals, supported or unsupported, with or without metal andalkali promoters, (c) mixed metal oxides of Co or Ni with Cu with orwithout a trivalent metal ion and/or alkali promoters, and (d) mixturesthereof; and a second group which includes (a) an alkali and/or metalpromoted ZnCrO, MnCrO and ZnMnCrO, (b) alkali and/or metal promotedCu/ZnO materials, and (c) mixtures thereof, and mixtures of the firstand second groups. Preferably, the alcohol synthesis catalyst or alcoholsynthesis catalytic component is selected from among those catalystsused commercially to make methanol from a synthesis gas, which arehighly developed and their activity and selectivity are known. Theyinclude: (a) Cu/ZnO (with or without Al), (b) Cu-rare earth metals, and(c) supported Group 7, 8, 9 and/or 10 metals. These catalysts generatemethanol from a synthesis gas according to the following reaction:

    2H.sub.2 +COCH.sub.3 OH

Alcohol synthesis catalysts or alcohol synthesis catalytic componentsthat typically generate from synthesis gas an Anderson-Schultz-Floryproduct distribution of linear alcohols include (a) alkali and/or metalspromoted MoS₂ -based materials, (b) Group 7, 8, 9 and/or 10 metals, withor without metal promoters and alkali, and (c) mixed metal oxides of Coor Ni and Cu, with or without a trivalent metal ion and/or alkalipromoters. These catalysts or catalytic components generate linearalcohols from synthesis gas according to the following reaction:

    xH.sub.2 +yCOR--CH.sub.2 OH+zH.sub.2 O

where x, y and z are the required stoichiometric coefficients, and R isH or an alkyl group of 1 to about 12 carbon atoms. Linking together thealcohol synthesis catalyst and alcohol carbonylation catalyst fromseparate reactors or coupling the alcohol synthesis catalytic componentwith the alcohol carbonylation catalytic component in a single reactoryields linear carboxylic acids according to the overall reaction:

    xH.sub.2 +yCO→RCH.sub.2 C(O)OH+zH.sub.2 O

where x, y and z are the required stoichiometric coefficients, and in Ris H or an alkyl group of 1 to about 12 carbon atoms.

Alcohol catalysts and alcohol catalytic components that typicallygenerate from synthesis gas a non-Anderson-Schultz-Flory distribution ofmethanol, ethanol and 2-methyl branched higher alcohols, e.g.,isobutanol, include (a) alkali and/or metal promoted ZnCrO, MnCrO andZnMnCrO, and (b) alkali and/or metal promoted Cu/ZnO materials. Thesecatalysts and catalytic components generate branched alcohols accordingto the following reaction: ##STR3## where x, y and z are the requiredstoichiometric coefficients, and R is H or an alkyl group of 1 to about12 carbon atoms. Linking together the alcohol synthesis catalyst andalcohol carbonylation catalyst from separate reactors or coupling thealcohol synthesis catalytic component with the alcohol carbonylationcatalytic component in a single reactor yields non-linear carboxylicacids according to the overall reaction: ##STR4## where x, y and z arethe required stoichiometric coefficients, and R is H or an alkyl groupof 1 to about 12 carbon atoms.

In the embodiment of this invention which involves converting afeedstock comprising at least one alcohol, ether, ether alcohol ormixtures thereof to a product stream comprising at least one of anester, acid, acid anhydride and mixtures thereof, suitable feedstocksmay include, for example, mono- and polyhydric alcohols, alkyletherssuch as alkyl or alkylene mono- and polyethers, and alkyl ether alcoholsand mixtures thereof. Such compounds may contain aromatic rings. Thepreferred alcohols, ethers and ether alcohols that may be carbonylatedby the processes of this invention include alkanols of 1 to about 20carbon atoms, alkane polyols of 2 to about 24 carbon atoms, alkylmonoethers of 2 to about 20 carbon atoms, alkyl alkylene polyethers of 4to about 40 carbon atoms and alkoxyalkanols of 3 to about 20 carbonatoms. Illustrative alcohols, ethers and ether alcohols that may becarbonylated in accordance with this invention are disclosed in U.S.Pat. Nos. 5,218,140 and 5,330,955, the disclosures of which areincorporated herein by reference. The feedstocks comprising at least onealcohol, ether, ether alcohol or mixtures thereof may be prepared asdescribed herein or alternatively may be obtained from a differentsource and fed directly to the carbonylation catalyst.

In such carbonylation embodiment, the processes involve providing atleast one of the alcohol, ether, ether alcohol and mixtures thereof inthe vapor state and passing the vapor over a bed containing the solidcatalyst comprising a super acid, clay, zeolite, or molecular sieveunder conditions described above. Preferably, the solid super acid,clay, zeolite and molecular sieve are impregnated with a Group 7, 8, 9,10 and/or 11 metal as described herein.

The carbonylation reaction may be carried out in a tubular reactor usinga fixed bed of the catalyst. The reactants may be fed to the catalyst byfeeding down or up, or a combination of both, to a fixed bed located ina tubular reactor. It may be desirable to use a reactor design thatoperates by plug flow and causes minimal turbulence in the reactor zone.The carbonylation reaction may be effected in a dynamic bed of thecatalyst. In such a reaction, the bed of catalyst is moving such as inthe case of a fluid bed of the catalyst.

Where the alcohol, ether, ether alcohol reactant is a higher boilingmaterial not easily vaporized, it can be diluted with a lower boilingnonreactive solvent or diluent and thus transported over the solidcatalyst. The degree of dilution in some cases can be quite extreme andof course, such conditions will adversely affect the cost ofcarbonylation. Suitable solvents and diluents include aliphatic andaromatic hydrocarbons, esters, non-condensable ketones, and the like.

The alcohol carbonylation catalysts and alcohol carbonylation catalyticcomponents useful in the processes of this invention include solidacidic materials, for example, solid super acids, heteropoly acids,clays, zeolites, molecular sieves, and the like. Two or more permissiblealcohol carbonylation catalysts or alcohol carbonylation catalyticcomponents may be used in a combined form. Illustrative of suitablealcohol carbonylation catalysts and alcohol carbonylation catalyticcomponents include those permissible solid acidic materials described inTsutomu Yamaguchi, "Recent Progress in Solid Superacid", AppliedCatalysis, 61, (1990), 1 and "Zeolite, Clay, and Heteropoly Acid inOrganic Reactions", by Yusuke Izumi, Kazuo Urabe and Makato Onaka, VCHPublishers Inc., 1992, the pertinent portions of which are incorporatedherein by reference.

The alcohol carbonylation catalysts and alcohol carbonylation catalyticcomponents exhibit an acid strength of less than or equal to -5.0(Ho≦-5.0), preferably less than or equal to -10.0 (Ho≦-10.0), and morepreferably less than or equal to -12.5 (Ho≦-12.5). Acid strength ofsolid acids can be evaluated by conventional methods such as byestablishing Hammett acidity functions (Ho) using organic indicators asdescribed below.

When the color of a catalyst sample subjected to the determination iswhite, this sample is immersed in benzene and a benzene solutioncontaining an acid-base indicator of a known pKa value is added thereto.The sample is kept under observation until the indicator on the surfaceof the sample assumes the color of acidity. The smallest value of pKa atwhich the color of acidity is assumed is reported as the acid strengthof the sample. The indicators (pKa) which are usable for thisdetermination include, for example, m-nitrotoluene (-12.0),p-nitrotoluene (-12.4), p-nitrochlorobenzene (-12.7),m-nitrochlorobenzene (-13.2), 2,4-dinitrotoluene (-13.8), and1,3,5-trinitrobenzene (-16.0).

Solid super acid catalysts are preferred carbonylation catalysts andcarbonylation catalytic components for use in this invention. Thepreferred solid super acids have an acidity stronger than 100% H₂ SO₄,i.e., Ho<-12.5. Illustrative examples of solid super acids are Fe₂ O₃--SO₄, SnO₂ --SO₄, TiO₂ --SO₄, ZrO₂ --SO₄ and ZrO₂ --B₂ O₃, ZrO₂ --MO₃,ZrO₂ --WO₃, Fe₂ O₃ --WO₃, sulfated metal oxides promoted with Pt, Fe,Mn, and halogen promoted SiO₂ /alumina. A solid super acid impregnatedwith a Group 7, 8, 9, 10 and/or 11 transition metal is a particularlypreferred catalyst or catalytic component. Illustrative of suitablesolid super acids include those permissible solid super acids describedin Tsutomu Yamaguchi, "Recent Progress in Solid Superacid", AppliedCatalysis, 61, (1990), 1, supra.

The solid super acids and methods for their preparation are known. See,for example, EP Patent Application 0 685 259 A2 and U.S. Pat. No.5,780,383, the disclosures of which are incorporated herein byreference. Preferred alcohol carbonylation catalysts and catalyticcomponents are obtained when certain solid super acids such as Group 4,5 and/or 6 metal oxides and mixtures thereof are impregnated with aGroup 7, 8, 9, 10 and/or 11 metal and mixtures thereof. The weightpercent of Group 7, 8, 9, 10 and/or 11 metals impregnated onto Group 4,5 and/or 6 metal oxides can range from about zero to about 10 weightpercent or greater, preferably from about 0.001 weight percent to about5 weight percent. The weight percent of Group 6 metal oxides, i.e., MoO₃and WO₃, in said Group 4, 5 and/or 6 metal oxide super acids can rangefrom about 1 to about 40 weight percent or greater, preferably fromabout 10 weight percent to about 30 weight percent. The catalystscarbonylate methanol, dimethyl ether, and methyl acetate with synthesisgas in the vapor phase or in the liquid phase, e.g., as a slurry.

As indicated above, no halides, e.g., methyl iodide, are required in theliquid or vapor phases of the feedstock streams and/or recycle streamsof the processes of this invention, thus providing substantial economicbenefits in the design of equipment to carry out the processes. It isunderstood that halides which are fixed onto the catalyst or otherwiseare an integral part of the catalyst are permissible in the processes ofthis invention.

The preferred solid super acids are based on Group 4 metal oxidesimpregnated with Mo or W. Thus, the preferred solid super acids aremixtures of Ti--W, Ti--Mo, Zr--W, Zr--Mo, Hf--W, and Hf--Mo oxides.Mixtures of the oxides, such as Zr--W--Ti or Ti--Mo--Hf, are also usefulsolid super acid catalysts. Tungsten oxide, molybdenum oxide, ortungsten-molybdenum composite oxide/zirconium oxide super acids are alsopreferred. These solid super acids are expressed as WO₃ /ZrO₂, MoO₃/ZrO₂, and WO₃ --MoO₃ /ZrO₂. Solid super acids of tungsten oxide/tinoxide, titanium oxide, iron oxide, or composite oxide of at least twoelements selected among tin, titanium and iron are further preferred.These solid super acids are expressed as WO₃ /SnO₂, WO₃ /TiO₂, WO₃ /Fe₂O₃, WO₃ /SnO₂ --TiO₂, WO₃ /SnO₂ --Fe₂ O₃, WO₃ /TiO₂ --Fe₂ O₃, and WO₃/SnO₂ --TiO₂ --Fe₂ O₃ The solid super acids can serve as the support inaddition to serving as an integral part of the catalyst. A preferredcatalyst and catalytic component consists of a manufactured solid superacid pellet that is impregnated by an appropriate Group 7, 8, 9, 10and/or 11 metal.

Supported catalysts are also useful in this invention. For example, anactive catalyst may be obtained by loading Group 4 or 5, Mo or Wprecursors onto alumina, silica, various clays, etc., and thentransforming (via calcination) the precursors into a supported solidacid. This material may then be impregnated with the Group 7, 8, 9, 10and/or 11 metal. The Group 9 and 10 metals yield particularly activecatalysts. The preferred Group 9 and 10 metals are Ir, Pd and Pt. Thesolid super acids impregnated with a Group 7, 8, 9, 10 and/or 11 metalcan be used separately or as a mixture and exhibit good selectivity andthermal stability. Pd--ZrO₂ --WO₃ is a preferred solid super acidcatalyst for use in this invention.

As indicated above, it has been discovered that hydrogen or a feedstockcontaining hydrogen, e.g., synthesis gas, has an unexpected stabilizingeffect on the heterogeneous alcohol carbonylation catalyst and alcoholcarbonylation catalytic component as compared to reactions in which onlymethanol and carbon monoxide are present in the system. While notwishing to be bound to any particular mechanism or theory, it isbelieved that the presence of hydrogen may play an important role ingenerating an active alcohol carbonylation catalyst and alcoholcarbonylation catalytic component by means of hydrogen spillover, i.e.,hydrogen atoms migrate (spill over) from the metal to the metal oxidesurface forming acidic sites where carbonylation occurs. Thisstabilizing effect is particularly beneficial for alcohol carbonylationcatalysts and alcohol carbonylation catalytic components such as ZrO₂--WO₃ impregnated with low levels Group 7, 8, 9, 10 and/or 11 metals,e.g., Pd, Pt, Rh, Ir, Ru, Re and Os. Illustrative metals which promotethis stabilizing effect include Group 7, 8, 9, 10 and 11 metals, e.g.,Ag, Cu, physical mixtures of Pd, Pt, Rh, Ir, Ru, Os supported on Al₂ O₃or SiO₂ physically mixed with a Group 4 solid super acid and the like.

The amount of hydrogen is not narrowly critical and should preferably bean amount sufficient to impart the desired stabilizing effect on theheterogeneous alcohol carbonylation catalyst and alcohol carbonylationcatalytic component. Suitable hydrogen partial pressures may range, forexample, from about 0.1 psig or less to about 9000 psig or greater, orfrom about 0.1 psig or less to about 4500 psig or greater, or from about0.1 psig or less to about 2700 psig or greater. Hydrogen may be fedseparately to the carbonylation reactor or in combination with otherfeedstock components, e.g., as synthesis gas or as part of a feed streamfrom a separate reactor as described herein.

Other illustrative solid super acids useful in this invention includesulfuric acid-carried solid super acids such as disclosed in EP PatentApplication 0 685 259 A2. As typical examples of these kinds, thefollowing solid super acids may be cited:

(1) solid super acids of SO₄ /oxide of a metal of Groups 4 and 14, e.g.,SO₄ /zirconium oxide, SO₄ /titanium oxide, SO₄ /tin oxide and SO₄/hafnium oxide, represented as SO₄ /ZrO₂, SO₄ /TiO₂, SO₄ /SnO₂ and SO₄/HfO₂ respectively.

(2) SO₄ /iron oxide solid super acid, e.g., SO₄ /Fe₂ O₃.

(3) SO₄ /silicon oxide solid super acid, e.g., SO₄ /SiO₂.

(4) SO₄ /aluminum oxide solid super acid, e.g., SO₄ /Al₂ O₃.

Another category of alcohol carbonylation catalysts and catalyticcomponents include heteropoly acids such as disclosed in U.S. Pat. Nos.5,218,140 and 5,330,955, supra. Preferred heteropoly acids exhibit anacid strength of less than or equal to -1.0 (Ho≦-1.0), preferably lessthan or equal to -5.0 (Ho≦-5.0). Such alcohol carbonylation catalystsand catalytic components contain a polyoxometalate ion in which a metal,or mixture of metals, selected from Groups 4, 5, 6 and 7 metals iscomplexed with a cation from a member of Group 7, 8, 9, 10 and/or 11metals. More preferably this alcohol carbonylation catalyst andcatalytic component consists of a Group 7, 8, 9, 10 and/or 11 metalcation complexed with a heteropoly acid anion. Mixtures of heteropolyacids may be employed in the processes of this invention. The preferredheteropoly acids are represented by the formulae:

    M.sub.a Q.sub.b O.sub.c

or

    M.sub.a Q.sub.b O.sub.c Z.sub.d

or mixtures thereof wherein M is at least one metal selected from Group7, 8, 9, 10 and/or 11 metals, Q is one or more of a Group 4, 5 and/or 6metal, e.g., tungsten, molybdenum, vanadium, niobium, chromium andtantalum, O is oxygen, Z is one or more of phosphorus, arsenic, siliconor antimony, and a, b, c and d are each integers having valuessufficient to fulfill the molecular stoichiometry. In particular, a isan integer having a value of from 1 to about 5 or greater, b is aninteger having a value of from 1 to about 20 or greater, c is an integerhaving a value of from 1 to about 60 or greater, and d is a value havinga value of from 1 to about 5 or greater.

More particularly, one such heterogeneous alcohol carbonylation catalystand catalytic component is M[Q₁₂ ZO₄₀ ], wherein M is a Group 7, 8, 9,10 and/or 11 metal, or a combination of Group 7, 8, 9, 10 and/or 11metals, Q is one or more of Group 4, 5 and/or 6 metals, e.g., tungsten,molybdenum, vanadium, niobium, chromium, and tantalum, Z is phosphorus,antimony, silicon or arsenic, and O is oxygen. A more preferredembodiment of this alcohol carbonylation catalyst and catalyticcomponent is M[Q₁₂ PO₄₀ ], where M is Rh, Pd, Co, Ir, Ru andcombinations thereof, and Q is tungsten or molybdenum. A most preferredembodiment of this alcohol carbonylation catalyst and catalyticcomponent is MW₁₂ PO₄₀, wherein M is Ir, Ru, Rh, Pd and combinationsthereof. Other preferred heteropoly acids include phosphorous tungstateand/or an alkali metal salt thereof. These heteropoly acids areexpressed as H₃ P₁ W₁₂ O₄₀ and H_(3-x) A_(x) P₁ W₁₂ O₄₀, wherein A is analkali metal (sodium, potassium, rubidium, and/or cesium) and x is above0 and below 3 (0<×<3). Illustrative of suitable heteropoly acids includethose permissible heteropoly acids described in "Zeolite, Clay, andHeteropoly Acid in Organic Reactions", by Yusuke Izumi, Kazuo Urabe andMakato Onaka, VCH Publishers Inc., 1992, supra.

Other useful alcohol carbonylation catalysts include clays. Clays mayalso serve as a support for the alcohol carbonylation catalysts.Preferred clays exhibit an acid strength of less than or equal to -1.0(Ho≦-1.0), preferably less than or equal to -5.0 (Ho≦-5.0). The weightpercent of Group 7, 8, 9, 10 and/or 11 metals that may be impregnatedonto clays can range from about zero to about 10 weight percent,preferably from about 0.001 weight percent to about 5 weight percent.Clay is a label applied to a generic class of materials comprised oflayers of aluminosilicate with complex intercalation chemistry. Ingeneral, the layers have an overall negative charge which is balanced byhydrated cations occupying the interlayer space. The acidity of clayscan be modified by exchanging the interlayer cations. The strong acidityof clays originates in the dissociation of surface Si--OH groups andfrom the intercalated cations. Ion exchange with suitable largeinorganic cations leads to pillared clays, which can be potential shapeselective catalysts. Preferred pillared clays have increased surfaceareas and thermal stability. Careful selection of cations for clay ionexchange can lead to pillared clays with large well defined spacesbetween layers (referred to as galleries), that can be useful asselective catalysts. Suitable clays useful in this invention include,for example, montmorillonite, bentonite, kaolinite, and the like,including mixtures thereof. Illustrative of suitable clays include thosepermissible clays described in "Zeolite, Clay, and Heteropoly Acid inOrganic Reactions", by Yusuke Izumi, Kazuo Urabe and Makato Onaka, VCHPublishers Inc., 1992, supra.

Still other useful alcohol carbonylation catalysts include molecularsieves of the zeolitic variety, i.e., zeolites, and molecular sieves ofthe non-zeolitic variety, i.e., molecular sieves. Preferred zeolites andmolecular sieves exhibit an acid strength of less than or equal to -1.0(Ho≦-1.0), preferably less than or equal to -5.0 (Ho≦-5.0). The weightpercent of Group 7, 8, 9, 10 and/or 11 metals that may be impregnatedonto zeolites and molecular sieves can range from about zero to about 10weight percent, preferably from about 0.001 weight percent to about 5weight percent. Illustrative zeolites useful in this invention include,for example, LZ-10, LZ-20, 4A, 5A, 13X, 10X, Y, SK40, SK41, chabazite,faujasite, levynite, gismondine, erionite, sodalite, analcime,gmelinite, harmotome, mordenite, epistilbite, heulandite, stilbite,edingtonite, mesolite, natrolite, scolecite, thomsonite, brewsterite,laumontite, phillipsite, the ZSM's (ZSM-5, ZSM-20, ZSM-12, and ZSM-34),and the like, including mixtures thereof. Illustrative zeolites usefulin this invention are disclosed in U.S. Pat. Nos. 3,702,886, 3,972,983,3,832,449, 4,086,186 and 3,308,069, the disclosures of which areincorporated herein be reference.

Illustrative molecular sieves useful in this invention include, forexample, the silica molecular sieves, such as silicalite (S115) asdepicted in U.S. Pat. Nos. 4,061,724 and 4,073,865, the disclosures ofwhich are incorporated herein by reference. Other molecular sievesuseful in this invention include crystalline microporous molecular sieveoxides that are based on the presence of aluminophosphate in theframework of the crystal structures, e.g., those commonly known by theacronyms SAPO, MeAPO, FAPO, MAPO, MnAPO, CoAPO, ZAPO, MeAPSO, FAPSO,MAPSO, MnAPSO, CoAPSO, ZAPSO, ElAPO, ElAPSO and the like, includingmixtures thereof. Such molecular sieves are described, for example, inU.S. Pat. Nos. 4,567,029, 4,440,871, 4,500,651, 4,554,143 and 4,310,440,the disclosures of which are incorporated herein by reference.

The zeolites and molecular sieves preferably have a pore size greaterthan about 5 Angstrom units and less than about 10 Angstrom units,preferably between about 5.2 and about 8 Angstrom units, and morepreferably between about 5.5 and about 6.5 Angstrom units. Of course thezeolites and molecular sieves may contain meso- and macro-pores alongwith the preferred pore sizes. Mixtures of zeolites and molecular sievesmay be employed in the processes of this invention. Illustrative ofsuitable zeolites and molecular sieves include those permissiblezeolites and molecular sieve materials described in "Zeolite, Clay, andHeteropoly Acid in Organic Reactions", by Yusuke Izumi, Kazuo Urabe andMakato Onaka, VCH Publishers Inc., 1992, supra.

As indicated above, the catalysts and catalytic components of thisinvention may be utilized with or without support. However, when asupport is employed, the catalyst can be produced by depositing thecatalytic components on the support either separately or in combination.The support can be selected from the group of silica, gamma alumina,titania, zirconia, alumina silicates, clays, and activated carbon,although other supports may be used. As described herein, certainsupports such as clays may also be employed as the alcohol carbonylationcatalyst or catalytic component. Mixed composite supports in which ahigh surface area support is deposited over a lower surface area supportmay also be used. The surface area of the support does not appear to becritical to obtaining the benefits of this invention; thus, supportswithin a wide range of surface areas, e.g., at least about 1 squaremeter per gram or higher (as determined by BET) should suffice.

The catalyst may be present in the reactor in any of a variety of forms.It may be present as a physical admixture or blend of each of thecatalytic components, a uniform catalyst prepared by knownco-precipitation techniques, continuous or discontinuous portions orlayers of the different components impregnated into or coated on asupport, or as staggered, alternating or, simply, distinct portions ofthe different components placed within the reactor.

Conventional impregnation procedures can be used in instances in whichthe catalyst is impregnated into a support. The impregnation process canbe as simple as contacting the support with a solution containing bothcomponents or separate solutions each containing one component, followedby heating the coated support to a temperature and for a period of timein which the solvent(s) is(are) removed but which does not significantlyadversely affect the catalytic activity of the catalytic component(s).Typically, such temperatures may range from about 100° C. to about 900°C. for a period of time ranging from a few seconds up to about 8 hoursor more. Alternatively, precipitation of one or more of the componentseither in combination or separately may be useful in preparing supportedcatalysts. The precipitation can be accomplished either on the supportsurface or in the pores. Such precipitation may be carried out byconventional methods.

The use of heterogeneous alcohol carbonylation catalysts or alcoholcarbonylation catalytic components as described herein permits thereaction to proceed without the addition of an iodide promoter, such asCH₃ I and/or HI which are highly corrosive, necessitate the use ofexpensive corrosion resistant materials of construction and requireextensive separation procedures to remove the iodide from the productstream.

For the multicomponent catalysts of this invention, the weight ratio ofthe alcohol synthesis catalytic component to the alcohol carbonylationcatalytic component present in the catalyst should be such that thedesired product stream is produced. The weight ratio may vary from about50:1 to 1:50, with an especially preferred weight ratio of thesecatalytic components being about 10:1 to 1:10. The specific ratioselected will depend upon such factors as the activity and selectivityof each catalytic component, the reaction conditions, the desiredproduct stream composition, etc. and can readily be determined by oneskilled in the art from routine experimentation from the teachingsprovided herein.

The processes and catalysts of this invention enable the production ofoxygenates at desirable reaction rates. In the embodiment which employsa multicomponent catalyst in a single reaction zone, the catalystcomponents can be varied so as to control reaction rates. In theembodiment which employs an alcohol synthesis catalyst in a firstreaction vessel and a carbonylation catalyst in a second reactionvessel, the two catalysts can be varied so as to control reaction rates.Reaction rates are not narrowly critical and preferably are at leastabout 0.5 pounds of product per cubic foot of catalyst per hour (0.5lb/ft3 cat/hr) and more preferably at least about 1.0 lb/ft3 cat/hr. Theparticular reaction rates will be governed by the best compromisebetween achieving high catalyst selectivity, lifetime and ease ofoperability, as well as the intrinsic reactivity of the startingmaterials and the stability of the starting materials and the desiredreaction product to the reaction conditions.

Further, the processes and catalysts of this invention enable theproduction of oxygenates at desirable selectivities. In the embodimentwhich employs a multicomponent catalyst in a single reaction zone, thecatalyst components can be varied so as to control productselectivities. In the embodiment which employs an alcohol synthesiscatalyst in a first reaction vessel and a carbonylation catalyst in asecond reaction vessel, the two catalysts can be varied so as to controlproduct selectivities. Product selectivities are not narrowly criticaland preferably are at least about 25 percent and more preferably atleast about 50 percent of the desired product. The particularselectivities will be governed by the best compromise between achievinghigh catalyst activity, lifetime and ease of operability, as well as theintrinsic reactivity of the starting materials and the stability of thestarting materials and the desired reaction product to the reactionconditions.

Recovery and purification of desired products may be accomplished by anyappropriate means. The desired products of this invention may berecovered in any conventional manner and one or more separators orseparation zones may be employed in any given process to recover thedesired reaction product from its crude reaction product. Suitableseparation and purification methods include, for example, distillation,phase separation, extraction, absorption, crystallization, membrane,derivative formation and the like.

As described herein, the processes of this invention may involve one ormore recycle procedures. Gas and/or liquid recycle procedures may beemployed as appropriate. For example, as depicted in FIG. 1, the gaseousand liquid residuals are removed from the refining unit 12 via line 16and recycled to the reactor 8 via lines 16 and 18 and/or to the reformerunit 4 via lines 16 and 20. Also, as depicted in FIG. 2, the gaseous andliquid residuals are removed from the refining unit 13 via line 16 andrecycled to the reactor 8 via lines 16 and 18 and/or to the reformerunit 4 via lines 16 and 20.

The following more detailed description of preferred embodiments of thisinvention, the production of acetic acid in a one-reactor andtwo-reactor processes, is not intended to limit the scope of theinvention in any respect as the processes and catalysts may be utilizedfor the manufacture of other acids, esters, anhydrides and mixturesthereof using the concepts heretofore and hereafter fully and adequatelydisclosed.

In FIG. 1, which is a simplified flow diagram of an embodiment of thisinvention, a one-reactor process for the preparation of acetic acid froma hydrocarbon feed stream is shown. The hydrocarbon feed stream issupplied to a synthesis gas generation unit, 4, via line 2 wherein asynthesis gas comprising a mixture of hydrogen and carbon monoxide isgenerated and provides the feedstock to the reactor. The feedstock gasexits the synthesis gas generation unit via line 6 and enters thereactor 8. The reactor, containing a catalyst comprising an alcoholsynthesis catalytic component and an alcohol carbonylation catalyticcomponent, is maintained at pre-selected reaction conditions oftemperature and pressure so that a vapor phase reaction takes place inwhich the feedstock gas is converted to oxygenates, most preferablycontaining a large fraction of acetic acid. The product stream, ingaseous form, exits the reactor 8 via line 10 and enters a refining unit12, wherein the product stream is condensed to form a gas phase and aliquid phase. The refining unit is controlled so that a product streamconsisting essentially of acetic acid is removed from the refining unitvia line 14 and recovered essentially free of esters, anhydrides, andmixtures thereof. The gaseous and liquid residuals are removed from therefining unit via line 16 and recycled to the reactor 8 via lines 16 and18 and/or to the reformer unit 4 via lines 16 and 20.

In FIG. 2, which is a simplified flow diagram of an embodiment of thisinvention, a two-reactor process for the preparation of acetic acid froma hydrocarbon feed stream is shown. A hydrocarbon feed stream issupplied to a synthesis gas generation unit, 4, via line 2 wherein asynthesis gas comprising a mixture of hydrogen and carbon monoxide isgenerated and provides the feedstock to the alcohol synthesis reactor.The feedstock gas exits the synthesis gas generation unit via line 6 andenters the alcohol synthesis reactor 8. The alcohol synthesis reactor,containing an alcohol synthesis catalyst is maintained at pre-selectedreaction conditions of temperature and pressure so that a vapor phasereaction takes place in which the feedstock gas is converted to analcohol-containing stream, most preferably containing a large fractionof methanol or dimethyl ether. The product stream, in gaseous form,exits the reactor 8 via line 10 and enters a carbonylation reactor 11.The carbonylation reactor, containing an alcohol carbonylation catalyst,is maintained at pre-selected reaction conditions of temperature andpressure so that a vapor phase reaction takes place in which thealcohol-containing feedstock is converted to oxygenates, most preferablycontaining a large fraction of acetic acid or methyl acetate. Theproduct stream, in gaseous form, exits the reactor 11 via line 12 andenters a refining unit 13, wherein the product stream is condensed toform a gas phase and a liquid phase. The refining unit may be controlledso that a product stream consisting essentially of acetic acid isremoved from the refining unit via line 14 and recovered essentiallyfree of esters, anhydrides, and mixtures thereof. The gaseous and liquidresiduals are removed from the refining unit via line 16 and recycled tothe reactor 8 via lines 16 and 18 and/or to the reformer unit 4 vialines 16 and 20.

As shown in FIG. 2, the carbonylation reaction can be carried out bypassing the substrate to be carbonylated and synthesis gas over thecatalyst as a vapor phase reaction or as a liquid phase reaction, e.g.,a slurry reaction. As shown in FIG. 2, methanol can be formed in situ byfeeding synthesis gas to a methanol producing catalyst that is coupledto the carbonylation catalyst either in the same or different reactors.If desired, either methanol, synthesis gas or both can be obtained froma different source and fed directly to the carbonylation catalyst.

The reactors described with reference to FIGS. 1 and 2 may be a tube andshell design reactors, wherein the catalyst is a fixed bed catalyst andthe reaction takes place in the vapor phase. Other types of reactionsand, correspondingly, reactors that can be used include a fluidized bed,where the solid catalyst system is fluidized by the incoming gas stream,a slurry reactor where the catalyst is insoluble in the reaction media,or a bubble column reactor. When acetic acid is the desired product, itwill be the most corrosive component in the reactor so the material ofconstruction for the reactor need only be stainless steel, a relativelyinexpensive material as compared to the exotic materials, such asHastelloy C or zirconium clad Hastelloy, used in commercial processesemploying a homogeneous iodide-promoter.

From the above description, it should be readily apparent that thereactor and refining section are highly simplified when a vapor phasereaction is utilized because there is no liquid recycle of the catalystsystem. Moreover, because iodide promoters are not needed for thisinvention, apparatus to recover the highly corrosive iodide from theproduct stream can be eliminated.

One embodiment of this invention provides an integrated conversion whichpermits the use of a single reactor constructed of lower cost materialsto convert, in the presence of a unique multicomponent catalyst, afeedstock comprising hydrogen and carbon monoxide to, most preferably,acetic acid under uniform temperature and pressure processingconditions. While specific reference in describing the FIG. 1 has beenmade to the manufacture of acetic acid, this invention, as describedheretofore, is capable of producing any of a variety and/or combinationof oxygenates. A plurality of dual catalyst bed reactors may employed inthe practice of this invention. Likewise, a plurality of separatereactors for steps (a) and (b) described above may employed in anypermissible combination.

The processes of this invention may be carried out using, for example, afixed bed reactor, a fluid bed reactor, a continuous stirred tankreactor (CSTR) or a slurry reactor. The optimum size and shape of thecatalysts will depend on the type of reactor used. In general, for fluidbed reactors, a small, spherical catalyst particle is preferred for easyfluidization. With fixed bed reactors, larger catalyst particles arepreferred so the back pressure within the reactor is kept reasonablylow.

The processes of this invention can be conducted in a batch orcontinuous fashion, with recycle of unconsumed starting materials ifrequired. The reaction can be conducted in a single reaction zone or ina plurality of reaction zones, in series or in parallel or it may beconducted batchwise or continuously in an elongated tubular zone orseries of such zones. The materials of construction employed should beinert to the materials present during the reaction and the fabricationof the equipment should be able to withstand the reaction temperaturesand pressures. Means to introduce and/or adjust the quantity of startingmaterials or ingredients introduced batchwise or continuously into thereaction zone during the course of the reaction can be convenientlyutilized in the processes especially to maintain the desired molar ratioof the starting materials. The reaction steps may be effected by theincremental addition of one of the starting materials to the other.Also, the reaction steps can be combined by the joint addition of thestarting materials. When complete conversion is not desired or notobtainable, the starting materials can be separated from the product andthe starting materials then recycled back into the reaction zone.

For purposes of this invention, the chemical elements are identified inaccordance with the Periodic Table of the Elements reproduced in"Hawley's Condensed Chemical Dictionary" 12^(th) Edition, Revised byRichard J. Lewis, Sr., Van Nostrand Reinhold Company, New York, 1993.

The following examples are intended to demonstrate the unexpectedadvantages, uniqueness and superiority of the invention as compared tothe prior art.

EXAMPLE 1

The reaction system consists of a feed system, a fixed bed reactor, andan on-line analyzer. The system is capable of high temperature and highpressure operation. In the feed system, a synthesis gas feedstock isfirst passed through an activated carbon trap to remove metal carbonylcontaminants. The purified feedstock then passes through a mass flowmeter and into the reaction tube inlet. The reaction tube is stainlesssteel and is heated with an air fluidized sand bath. The gas productstream exiting the reactor enters into an analytical section equippedwith switching valves that provide 0.6 milliliter reactor off-gassamples that are analyzed in a Varian 3700 gas chromatograph equippedwith two detectors. H₂, N₂, CO and CO₂ are separated on a 10', 1/8",80/100 Carbosieve S-2 column purchased from Supelco and detected bythermal conductivity. All organic products are resolved on a 12', 1/8",80/100 Tenax column obtained from Alltech and detected using flameionization. Argon is used as the carrier gas for both columns.

A reactor tube was first charged with quartz beads followed by 1.0 gramof a Cu--Zn oxide methanol synthesis catalytic component (UnitedCatalyst No. 2537-S) that was bulk mixed with 2 grams of quartz beads.This catalytic component was reduced at 270° C. in a 5% H₂ /95% N₂stream for 6 hours.

As the heterogeneous alcohol carbonylation catalytic component aniridium and palladium exchanged H₃ W₁₂ PO₄₀ heteropoly acid catalyticcomponent was used. The component was prepared by the proceduredescribed in U.S. Pat. No. 5,330,955, as follows:

Pd(NO₃)₂ (0.23 grams) and IrCl₃.3H₂ O (0.37 grams) were added to 50milliliters of degassed methanol under N₂ in a Schlenk flask and stirredfor 0.5 hour. Next, H₃ W₁₂ PO₄₀ (6.50 grams) was added and the mixturewas stirred for an additional 1 hour. Activated Grade 12 silica gel(SiO₂) was added and the slurry stirred for 4 hours. The methanol wasthen removed at 80° C., under vacuum, yielding Ir--Pd--H₃ W₁₂ PO₄₀--SiO₂. This catalytic component has essentially the same compositionreported for Example 17 of U.S. Pat. No. 5,330,955, where the mole ratioof M1:M2:H₃ W₁₂ PO₄₀ is approximately 1:1:2 with M1 being iridium and M2being palladium.

The reactor tube was opened and 2.069 grams of Ir--Pd--H₃ W₁₂ PO₄₀--SiO₂ mixed with 2 grams of quartz beads was added to Cu--Zn oxidemethanol catalytic component in the reactor. The reactor tube was thenconnected to the reaction system and the entire system flushed withnitrogen. The reactor bed was packed in such a way that the incomingsynthesis gas first contacted the Cu--Zn catalytic component, and thenthe reaction stream contacted the Ir--Pd--H₃ W₁₂ PO₄₀ --SiO₂.

The reaction zone was maintained at a uniform temperature of about 235°C. and a uniform pressure of about 1000 psig with the synthesis gashaving a hydrogen to carbon monoxide molar ratio of 1:1. The GHSV of thesyn gas fed to the reactor was 6000/hr. After 16 hours of reaction asample of the reaction menstruum was analyzed. The analysis showed thecarbon monoxide conversion was about 5% and the reaction productdistribution was CH₄ =15.1%, C₂ H₆ =4.1%, CH₃ OH=62.1%, and CH₃COOH=17.5%.

The catalyst was relatively stable over the test period of 168 hours.The stability of the catalyst was surprising because the heterogeneousalcohol carbonylation catalytic compound significantly deactivated after8 hours when only methanol and carbon monoxide were fed to the reactor.The presence of hydrogen and carbon monoxide in the reactor appears tobe the reason for the unexpected increase in the stability of theheterogeneous alcohol carbonylation catalytic component of the catalyst.

EXAMPLE 2

A Ir--Pd--H₃ W₁₂ PO₄₀ -Carbon catalyst was prepared as follows. Pd(NO₃)₂(0.23 grams) and IrCl₃.3H₂ O (0.37 grams) were added to 50 millilitersof degassed methanol under N₂ in a Schlenk flask and stirred for 0.5hour. Next, H₃ W₁₂ PO₄₀ (6.50 grams) was added and the mixture wasstirred for an additional 1 hour. Activated Carbon (3.90 grams, Calgon35-100 mesh) was added and the slurry stirred for 4 hours. The methanolwas evaporated and Ir--Pd--H₃ W₁₂ PO₄₀ -Carbon was recovered.

2.002 grams of Ir--Pd--H₃ W₁₂ PO₄₀ -Carbon was charged to the reactor asdescribed in Example 1 and the reaction was carried out similar toExample 1 at 235° C. and 1000 psig with H₂ :CO=1:1. After 16 hours ofreaction a sample of the reaction menstruum was analyzed. The analysisshowed the carbon monoxide conversion was about 7% and the productdistribution was CH₄ =45.4%, C₂ H₆ =7.7%, CH₃ OH=30.1%, and CH₃COOH=13.1%.

EXAMPLE 3

A Ir--Pd--Cs--H₃ W₁₂ PO₄₀ catalyst was prepared as follows. Pd(NO₃)₂(0.23 grams) and IrCl₃.3H₂ O (0.37 grams) were added to 50 millilitersof degassed methanol under N₂ in a Schlenk flask and stirred for 0.5hour. Next, H₃ W₁₂ PO₄₀ (6.50 grams) was added and the mixture wasstirred for an additional 4 hours. After this time CsCO₃ (0.67 grams)was added and within 2 minutes a precipitate formed. This mixture wasstirred for 16 hours after which the methanol was removed by vacuum anda gray powder (Ir--Pd--Cs--H₃ W₁₂ PO₄₀) was recovered.

2.001 grams of Ir--Pd--Cs--H₃ W₁₂ PO₄₀ was charged to the reactor, inthe absence of a support, as described in Example 1 and the reaction wascarried out similar to Example 1 at 235° C. and 1000 psig with H₂:CO=1:1. After 16 hours of reaction a sample of the reaction menstruumwas analyzed. The analysis showed the carbon monoxide conversion wasabout 6% and the product distribution was CH₄ =32.8%, C₂ H₆ =4.4%, CH₃OH=45.1%, and CH₃ COOH=15.9%.

EXAMPLE 4

A Ru--H₃ W₁₂ PO₄₀ --SiO₂ catalyst was prepared as follows. RuCl₃ (0.27grams) was dissolved in 50 milliliters of degassed methanol. Next, H₃W₁₂ PO₄₀ (6.50 grams) was added and the mixture was stirred for anadditional 4 hours. SiO₂ (3.90 grams, Grade 15) was added and the slurrystirred for 4 hours. The methanol was evaporated and Ru--H₃ W₁₂ PO₄₀--SiO₂ was recovered.

2.001 grams of Ru--H₃ W₁₂ PO₄₀ --SiO₂ was charged to the reactor asdescribed in Example 1 and the reaction was carried out similar toExample 1 at 235° C. and 1000 psig with H₂ :CO=1:1. After 16 hours ofreaction a sample of the reaction menstruum was analyzed. The analysisshowed the carbon monoxide conversion was about 5% and the productdistribution was CH₄ =13.2%, C₂ H₆ and C₃ H₈ =10%, CH₃ OH=55.1%, and CH₃COOH=21.1%.

EXAMPLE 5

A Ru--H₃ W₁₂ PO₄₀ -Carbon catalyst was prepared as described in Example4 except 3.90 grams of activated carbon was used instead of silica.2.003 grams of Ru--H₃ W₁₂ PO₄₀ -Carbon was charged to the reactor asdescribed in Example 1 and the reaction was carried out similar toExample 1 at 235° C. and 1000 psig with H₂ :CO=1:1. After 16 hours ofreaction a sample of the reaction menstruum was analyzed. The analysisshowed the carbon monoxide conversion was about 6% and the productdistribution was CH₄ =32.6%, C₂ H₆ and C₃ H₈ =6.2%, CH₃ OH=45.1%, andCH₃ COOH=15.9%.

EXAMPLE 6

A Rh--H₃ W₁₂ PO₄₀ --SiO₂ catalyst was prepared as follows. RhCl₃.3HO(0.28 grams) was dissolved in 50 milliliters of degassed methanol. Next,H₃ W₁₂ PO₄₀ (6.50 grams) was added and the mixture was stirred for anadditional 4 hour. SiO (3.90 grams, Grade 15) was added and the slurrystirred for 4 hours. The methanol was evaporated and Rh--H₃ W₁₂ PO₄₀--SiO₂ was recovered.

2.000 grams of Rh--H₃ W₁₂ PO₄₀ --SiO₂ was charged to the reactor asdescribed in Example 1 and the reaction was carried out similar toExample 1 at 235° C. and 1000 psig with H₂ :CO=1:1. After 16 hours ofreaction a sample of the reaction menstruum was analyzed. The analysisshowed the carbon monoxide conversion was about 7.2% and the productdistribution was CH₄ =22.8%, C₂ H₆ and C₃ H₈ =20.1%, CH₃ OH=36.1%, andCH₃ COOH=17.1%.

EXAMPLE 7

A Rh--H₃ W₁₂ PO₄₀ -carbon catalyst was prepared as described in Example6 except 3.90 grams of activated carbon was used instead of silica. 2.01grams of Rh--H₃ W₁₂ PO₄₀ -carbon was charged to the reactor and thereaction was carried out similar to Example 1 at 235° C. and 1000 psigwith H₂ :CO=1:1. After 16 hours of reaction a sample of the reactionmenstruum was analyzed. The analysis showed the carbon monoxideconversion was about 6.5% and the product distribution was CH₄ =15.9%,C₂ H₆ and C₃ H₈ =12.1%, CH₃ OH=53.2%, and CH₃ COOH=18.7%.

EXAMPLE 8

Preparation of ZrO₂ --WO₃ Solid Super Acid

82.3 grams of ZrOCl₂.8H₂ O were dissolved in 1 liter of distilled H₂ Ogiving a clear solution. 30% ammonium hydroxide was added drop wiseuntil the pH remained >9. Addition of the hydroxide results in theimmediate hydrolysis of ZrOCl₂.8H₂ O to Zr(OH)₄ and formation of aslurry. The slurry was stirred for about 1/2 hr and then filtered torecover the Zr(OH)₄. This gel-like material was dried at 120° C. for 16hours and yielded 32.5 grams of a white granular solid that was crushedinto a powder.

5.014 grams of Zr(OH)₄ powder were placed in a 50 milliliter beaker. TheZr(OH)₄ was impregnated via incipient wetness with 1.2204 grams of(NH₄)₆ H₂ W₁₂ O₄₀ dissolved in 10 milliliters of distilled H₂ O. The wetsolid was dried at 120° C. and then calcined at 800° C. in static airfor 4 hours. 5.471 grams of a lemon yellow powder were obtained. Thismaterial is considered to be the solid super acid ZrO₂ --WO₃ with anempirical WO₃ loading of 23 wt %.

EXAMPLE 9

Preparation of TiO₂ --WO₃ Solid Super Acid

30 milliliters of Ti(isopropyl)₄ was added dropwise to 500 millilitersof deionized water at room temperature over 30 minutes. The slurry wasstirred for 1 hour, filtered, air dried, and then placed in an oven todry at 120° C. for 16 hours. 8.834 grams of hydrated TiO₂ was obtained.This powder was impregnated with 1.9068 grams of (NH₄)₆ H₂ W₁₂ O₄₀dissolved in 15 milliliters of distilled H₂ O. The damp mixture was wellstirred, air dried for 1 hour, and then placed in an oven to dry at 120°C. for 16 hours. The mixture was then calcined at 800° C. for 4 hoursfrom which 9.85 grams of a lemon yellow solid was obtained. Thismaterial is considered to be the solid super acid TiO₂ --WO₃ with anempirical WO₃ loading of 23 wt %.

EXAMPLE 10

Preparation of HfO₂ --WO₃ Solid Super Acid

HfO₂ --WO₃ was prepared essentially the same as ZrO₂ --WO₃. 50.0 gramsof HfOCl₂.8H₂ O were dissolved in 0.5 liter of distilled H₂ O giving aclear solution. 30% ammonium hydroxide was added dropwise, with rapidstirring, until a pH of about 10 was obtained. The slurry was mixed for5 minutes, then was filtered to recover the Hf(OH)₄. The Hf(OH)₄ waswashed with 3 liters of distilled H₂ O and the gelatinous material wasdried at 120° C. for 16 hours. The resulting white, granular materialwas then crushed into a powder.

7.0 grams of Hf(OH)₄ was impregnated via incipient wetness with 1.0grams of (NH₄)₆ H₂ W₁₂ O₄₀ dissolved in 3 milliliters of distilled H₂ O.The wet solid was dried at 120° C. and then calcined at 700° C. instatic air for 3.5 hours to produce a green powder. This material isconsidered to be the solid super acid HfO₂ --WO₃ with an empirical WO₃loading of 13.5 wt %.

EXAMPLE 11

Preparation of Ir--ZrO₂ --WO₃

ZrO₂ --WO₃ was impregnated with Ir by incipient wetness. A variety ofsoluble Ir compounds can be used. For example, 0.0379 grams of IrCl₃.3H₂O were dissolved in 3 milliliters of distilled H₂ O. This solution wasadded drop wise with stirring to 2.0651 grams of ZrO₂ --WO₃. Once thesolid became damp addition of Ir was stopped and the solid was dried at120° C. This procedure was repeated until all the Ir solution wasutilized. The material was dried for 16 hours at 120° C. yielding 2.0365grams of a yellow-tan solid. This material is considered to beIr(1)-ZrO₂ --WO₃ (23) where (1) indicates the Ir metal loading in wt %metal basis.

EXAMPLE 12

Preparation of Pd--ZrO₂ --WO₃

ZrO₂ --WO₃ was impregnated with Pd by incipient wetness. A variety ofsoluble Pd compounds can be used. For example, 0.0026 grams of Pd(NO₃)₂·H₂ O were dissolved in 4.0 milliliters of distilled H₂ O and was addeddrop wise with stirring to 4.0 grams of ZrO₂ --WO₃. Once the solidbecame damp addition of Pd was stopped and the solid was dried at 120°C. This procedure was repeated until all the Pd solution was utilized.The material was dried for 16 hours at 120° C. to produce a brightyellow powder. This material is considered to be Pd(0.02)-ZrO₂ --WO₃(18) where (0.02) indicates the Pd metal loading in wt % metal basis.

EXAMPLES 13-19

For the following examples, the reactions were carried out in a 3/8" 316stainless steel reactor tube capable of high pressure operation. Thereactor was housed in a convection oven. Synthesis gas was supplied tothe reactor under pressure, as was any liquid feed. The product streamexiting the reactor was maintained as a vapor and sent to an online GCfor analysis. Regarding reactor tube loading, a reactor tube was firstcharged with quartz beads followed by 2 to 3 grams of the carbonylationcatalyst mixed with 2 grams of quartz beads. The reactor tube was thenconnected to the reaction system and the entire system was well flushedwith nitrogen. The gas feed was switched to synthesis gas and thereaction system brought to operating conditions. Liquid feed, if used,was then added. In the case of coupling a methanol catalyst with thecarbonylation catalyst, the reactor was first packed with the methanolcatalyst and then packed with the carbonylation catalyst. Synthesis gasfirst contacted the methanol catalyst and that product stream thencontacted the carbonylation catalyst. Table A below contains data forvarious catalysts prepared as described above used to carbonylatemethanol to methyl acetate or a mixture of methyl acetate and aceticacid. For all examples, the reaction was carried out at 1000 psig with1:1 H₂ :CO gas feed. Methanol was fed to the reactor as a neat liquid atthe reported LHSV. The results are set forth in Table A. The amounts (inparenthesis) of catalyst composition components set out in Table A aregiven as weight percents.

                                      TABLE A                                     __________________________________________________________________________           Pd  Pd  Pd  Pt  Ir  Ir   Pd                                               (0.5)- (0.5)- (0.02) (0.04) (0.04)- (0.02)- (0.1)-                            ZrO.sub.2 -- ZrO.sub.2 -- ZrO.sub.2 -- ZrO.sub.2 -- ZrO.sub.2 --                                           Pd(0.02)- ZrO.sub.2 --                           WO.sub.3 WO.sub.3 WO.sub.3 WO.sub.3 WO.sub.3 ZrO.sub.2 -- MoO.sub.3                                         Catalyst (23) (23) (18) (18) (18)                                            WO.sub.3 (23) (12)                            __________________________________________________________________________    Temperature,                                                                         320 330 300 300 300 300  300                                             ° C.                                                                   Feed, mole %                                                                  H.sub.2 43.45 47.8 45.4 45.4 45.4 45.4 45.4                                   CO 43.45 47.8 45.4 45.4 45.4 45.4 45.4                                        methanol 13.1 4.3 9.5 9.5 9.5 9.5 9.5                                         Inlet 12000 12000 9500 9500 9500 9500 9500                                    GHSV, hr.sup.-1                                                               Inlet 1.5 0.45 1.5 1.5 1.5 1.5 1.5                                            LHSV, hr.sup.-1                                                               Product stream,                                                               mole %                                                                        dimethyl 24.2 11.3 59.3 57.9 58.1 57.6 5.1                                    ether                                                                         methanol 21.6 16.8 27.6 25.6 27.5 27.4 56.1                                   methyl 25.1 8.5 7.1 7.2 8.1 7.3 7.7                                           acetate                                                                       acetic acid 8.8 28.5 0 0 0 0 0                                                methane 18.2 25.7 1.5 4.5 1.7 3.2 27.8                                        carbon 1.5 7.0 4.2 4.5 4.3 3.9 2.1                                            dioxide                                                                       Rate,                                                                         lb/ft.sup.3 cat/hr                                                            acetic acid 9.3 10.2 0 0 0 0 0                                                methyl 32.4 3.8 7.3 7.4 8.1 7.6 11.4                                          acetate                                                                       MeOH 47.3 66.2 12.7 15.1 15.2 13.6 41.2                                       conversion, %                                                                 CO 12.0 6.4 4.1 4.2 4.2 5.1 3.1                                               conversion, %                                                               __________________________________________________________________________

EXAMPLES 20-22

Various liquid feeds were carbonylated and the results are given inTable B below. The reactions were carried out similarly to Examples13-19. The results listed in column 1 demonstrate that dimethyl ether isreadily carbonylated to methyl acetate. The other results indicate thatmixtures of methyl acetate and methanol are carbonylated. These resultsare important with respect to mixtures of methanol, dimethyl ether, andmethyl acetate being recycled back to the reactor. The amounts (inparenthesis) of catalyst composition components set out in Table B aregiven as weight percents.

                  TABLE B                                                         ______________________________________                                                   Ir(0.1)-    Pd(0.1)- Pd(0.1)-                                         ZrO.sub.2 -- ZrO.sub.2 -- ZrO.sub.2 --                                       Catalyst WO.sub.3 (18) WO.sub.3 (23) WO.sub.3 (23)                          ______________________________________                                        Temper-    300         325      315                                             ature, ° C.                                                            Pressure, 1000 1000 1000                                                      psig                                                                          Feed, mole %                                                                  H.sub.2 48.4 47.9 46.2                                                        CO 48.4 47.9 46.2                                                             methanol 0 1.0 5.7                                                            methyl 0 3.2 1.9                                                              acetate                                                                       dimethyl 3.2 0 0                                                              ether                                                                         Inlet GHSV, 9000 11000 8200                                                   hr.sup.-1                                                                     Inlet LHSV, 0.75 1.36 1.36                                                    hr.sup.-1                                                                     Product                                                                       stream,                                                                       mole %                                                                        dimethyl 58.6 14.7 23.1                                                       ether                                                                         methanol 14.2 17.5 19.0                                                       methyl 13.1 39.5 36.6                                                         acetate                                                                       acetic acid 2.5 9.9 7.8                                                       methane 9.1 12.2 11.7                                                         carbon 1.2 2.7 1.3                                                            dioxide                                                                       Rate,                                                                         lb/ft.sup.3 cat/hr                                                            acetic acid 1.2 8.45 6.3                                                      methyl 7.4 --  --                                                             acetate                                                                       Methanol --  72.3 61.2                                                        conversion, %                                                                 CO 12.0 8.2 13.7                                                              conversion, %                                                               ______________________________________                                    

EXAMPLES 23-26

In the following examples, the reactor tube was first packed with aCu--Zn methanol producing catalyst followed by one of the catalystslisted in Table C below. The tube was placed in an oven and synthesisgas was passed through the tube contacting the methanol catalyst first.The gas mixture then passed through the carbonylation catalyst. Thetemperature and pressure were the same for both catalysts. In no casewas a liquid fed to the reactor. The results demonstrate that thecarbonylation catalyst can be coupled to a methanol producing catalystand that various Group 7, 8, 9, 10 and/or 11 metals form activecatalysts. The results are set forth in Table C. The amounts (inparenthesis) of catalyst composition components set out in Table C aregiven as weight percents.

                  TABLE C                                                         ______________________________________                                                  Ir(1.0)-  Rh(0.1)- Re(1.0)-                                                                              Os(1.0)-                                    TiO.sub.2 -- ZrO.sub.2 -- ZrO.sub.2 -- ZrO.sub.2 --                          Catalyst WO.sub.3 (23) WO.sub.3 (20) WO.sub.3 (23) WO.sub.3 (23)            ______________________________________                                        Temper-   275       300      300     275                                        ature, ° C.                                                            Pressure, 1000 1000 1000 1000                                                 psig                                                                          Feed, mole %                                                                  H.sub.2 50 50 50 50                                                           CO 50 50 50 50                                                                Inlet GHSV, 6300 7900 6000 6000                                               hr.sup.-1                                                                     Product                                                                       stream,                                                                       mole %                                                                        dimethyl 38.2 28.2 23.6 61.7                                                  ether                                                                         methanol 46.4 17.7 20.7 21.6                                                  methyl 1.8 5.5 3.5 1.9                                                        acetate                                                                       acetic acid 0.1 0 0.4 0.1                                                     methane 2.7 9.2 4.2 1.9                                                       carbon 10.0 33.2 42.3 11.4                                                    dioxide                                                                       Rate,                                                                         lb/ft.sup.3 cat/hr                                                            acetic acid 0.1 0 0.2 0.1                                                     methyl 1.1 4.7 2.9 1.1                                                        acetate                                                                     ______________________________________                                    

EXAMPLES 27-31

In each of these examples, methanol was carbonylated to a mixture ofmethyl acetate and acetic acid. The results are given in Table D below.The reactions were carried out in a manner similar to Examples 13-19.The results demonstrate that Group 10 and 11 metals impregnated ontocatalysts containing tungsten oxide and zirconium oxide are useful inthis invention.

                  TABLE D                                                         ______________________________________                                                                      Pres-                                                sure, Carbonylation                                                        Example Catalyst Temp, ° C. psi Rate lb/ft3 cat-hr*                  ______________________________________                                        27     Ag.sub.0.6 --ZrO.sub.2 --WO.sub.3                                                          300       1000 3.6                                          28 Ag.sub.0.25 --ZrO.sub.2 -- 325 1000 10.3                                    WO.sub.3                                                                     29 Cu.sub.0.5 --ZrO.sub.2 --WO.sub.3 300 1000 3.3                             30 Pt.sub.0.05 --Al.sub.2 O.sub.3 300 1000 3.1                                 mixed with ZrO.sub.2 --                                                       WO.sub.3                                                                     31 Pd.sub.5.0 --SiO2 mixed 300 1000 1.1                                        with ZrO.sub.2 --WO.sub.3                                                  ______________________________________                                         *Carbonylation rate is defined as acetic acid + acetic acid equivalents i     methyl acetate.                                                          

EXAMPLES 32-46

In each of these examples, methanol was carbonylated to a mixture ofmethyl acetate and acetic acid. The results are given in Table E below.The reactions were carried out in a manner similar to Examples 13-19.All examples were run at a pressure of 1000 psig, a H₂ :CO ratio of 1:1,and the alcohol synthesis catalyst was United Catalyst No. 2537-S. Theresults demonstrate that clays may be effectively used as the alcoholcarbonylation catalyst.

                  TABLE E                                                         ______________________________________                                                    GHSV hr.sup.-1                                                                        Productivity, lbs/ft.sup.3 cat/hr                                           1st    2nd               Total                                Catalyst ° C. Stage Stage HOAc MeOAc HC                              ______________________________________                                        Montmorillonite                                                                 H.sup.+  300 6000 3000 0.08 0.10 0.98                                         Al.sup.+3 300 6000 3000 0.04 0.08 0.63                                        Ir--Al.sup.+3 300 6000 3000 0.05 0.47 1.44                                    Fe.sup.+3 -pillared 300 6000 3000 0.05 0.09 0.95                              Ir--Fe.sup.+3 -pillared 250 6000 3000 0.02 0.27 0.65                          Ir--Fe.sup.+3 -pillared 300 6000 3000 0.05 3.21 6.53                          Bentonite                                                                     H.sup.+ 300 6000 3000 0.04 0.04 0.46                                          Ir--Al.sup.+3 300 6000 3000 0.31 0.14 1.62                                    Ir--Fe.sup.+3 300 6000 3000 0.09 0.05 1.26                                    Ir--Al.sup.+3 -pillared 300 6000 3000 0.87 0.10 1.21                          Ir--Fe.sup.+3 -pillared 300 6000 3000 0.15 0.11 1.23                          Ir--H.sup.+ -pillared 300 6000 3000 3.44 0.04 4.18                            Ir--H.sup.+ -pillared 250 6000 3000 2.64 0.02 3.32                            Ir-pillared 300 6000 3000 1.25 0.04 0.90                                    ______________________________________                                    

EXAMPLES 47-50

The following examples were conducted in a stainless steel tube reactorheated by a Lindberg furnace. Syn gas flows were metered by a Brooksmass flow controller while liquid feeds were delivered by a Gilson orIsco pump. The catalyst was ZrO₂ --WO₃ (18)-Pd(0.05) and was obtainedfrom Norton Corp. (Akron, Ohio), i.e., nominally contained 82 wt % ZrO₂and 18 wt % WO₃. This material was supplied as an extrudate. Prior tobeing used, this material was calcined at 810° C. for 3 hours and wasthen impregnated to 0.05 wt % Pd by incipient wetness. Liquid productswere collected in a condenser that was maintained at room temperature.Collected liquid products were analyzed by gas chromatography. Thereaction conditions for these examples were as follows:

Temperature=325° C.

Pressure=1000 psi

Syn gas=1:50 (H₂ :CO)

GHSV (hr⁻¹)=6000

LHSV (hr⁻¹)=1.5

The reactants and observed carbonylation products for these exampleswere as follows:

    ______________________________________                                        Reactant        Carbonylation Products                                        ______________________________________                                        ethanol         ethyl propionate, propionic acid                                diethyl ether ethyl propionate, propionic acid                                propanol n-butyric acid                                                       n-propyl ether n-butyric acid, propionic acid                               ______________________________________                                    

The foregoing description of the preferred embodiments of this inventionand the examples are presented for purposes of best teaching one skilledin the art how to practice the invention. It is not, nor is it intendedto be, an exhaustive description of every permutation of the invention.Obviously, many variations and modifications are possible in light ofthe disclosure and readily apparent to a person of ordinary skill in theart to which this invention pertains. It is intended that the full scopeof the invention be defined by the appended claims.

What is claimed is:
 1. A process for converting a feedstock comprisingcarbon monoxide and hydrogen to a product stream comprising at least oneof an ester, acid, acid anhydride and mixtures thereof which comprisesreacting the carbon monoxide and hydrogen in the presence of a catalystcomprising an alcohol synthesis catalytic component and an alcoholcarbonylation catalytic component, wherein said alcohol carbonylationcatalytic component comprises a solid super acid, clay or non-zeoliticmolecular sieve, in the presence of a halide promoter and underconditions of temperature and pressure sufficient to produce saidproduct stream, and wherein the reaction is conducted in a singlereaction vessel.
 2. The process of claim 1 wherein the alcoholcarbonylation catalytic component is a heterogeneous catalyticcomponent.
 3. The process of claim 1 wherein the alcohol carbonylationcatalytic component has an acid strength of less than or equal to -5.0(Ho≦-5.0).
 4. The process of claim 1 wherein the alcohol carbonylationcatalytic component comprises a solid super acid impregnated with aGroup 7, 8, 9, 10 and/or 11 metal and/or mixtures thereof.
 5. Theprocess of claim 4 wherein the amount of Group 7, 8, 9, 10 and/or 11metals and/or mixtures thereof impregnated onto said solid super acid isfrom about 0.001 to about 10 weight percent.
 6. The process of claim 1wherein said solid super acid comprises a Group 7, 8, 9, 10 and/or 11metal and/or mixtures thereof impregnated on a Group 4, 5 and/or 6 metaloxide and/or mixtures thereof, and wherein said solid super acidcontains from about 1 to about 40 weight percent of at least one Group 6metal oxide.
 7. The process of claim 6 wherein said solid super acidcatalyst comprises palladium and one or more zirconium oxides incombination with one or more tungsten oxides and/or molybdenum oxides.8. The process of claim 1 wherein the reaction is a vapor phasereaction.
 9. The process of claim 1 wherein the feedstock is synthesisgas consisting essentially of carbon monoxide and hydrogen and theproduct stream comprises acetic acid and/or methyl acetate.
 10. Aprocess for converting a feedstock comprising carbon monoxide andhydrogen to a product stream comprising at least one of an ester, acid,acid anhydride and mixtures thereof which comprises (a) reacting thecarbon monoxide and hydrogen in the presence of a catalyst underconditions of temperature and pressure sufficient to produce at leastone of an alcohol, ether, ether alcohol and mixtures thereof and (b)reacting carbon monoxide and said at least one of an alcohol, ether,ether alcohol and mixtures thereof in the presence of a catalystcomprising a solid super acid, clay or non-zeolitic molecular sieve inthe absence of a halide promoter and under conditions of temperature andpressure sufficient to produce said product stream.
 11. The process ofclaim 10 wherein steps (a) and (b) are carried out in separate reactionvessels.
 12. The process of claim 10 wherein the step (b) reaction iscarried out in the presence of hydrogen and/or synthesis gas.
 13. Aprocess for converting a feedstock comprising at least one of analcohol, ether, ether alcohol and mixtures thereof to a product streamcomprising at least one of an ester, acid, acid anhydride and mixturesthereof by reacting carbon monoxide and said at least one of an alcohol,ether, ether alcohol and mixtures thereof in the presence of a catalystcomprising a solid super acid, clay or non-zeolitic molecular sieve inthe absence of a halide promoter and under conditions of temperature andpressure sufficient to produce said product stream.
 14. The process ofclaim 13 wherein the catalyst comprises a solid super acid impregnatedwith a Group 7, 8, 9, 10 and/or 11 metal and/or mixtures thereof. 15.The process of claim 14 wherein the amount of Group 7, 8, 9, 10 and/or11 metals and/or mixtures thereof impregnated onto said solid super acidis from about 0.001 to about 10 weight percent.
 16. The process of claim13 wherein said solid super acid comprises a Group 7, 8, 9, 10 and/or 11metal and/or mixture thereof impregnated on a Group 4, 5 and/or 6 metaloxide and/or mixtures thereof, and wherein said solid super acidcontains from about 1 to about 40 weight percent of at least one Group 6metal oxide.
 17. The process of claim 13 wherein said solid super acidcatalyst comprises palladium and one or more zirconium oxides incombination with one or more tungsten oxides and/or molybdenum oxides.18. The process of claim 13 wherein the reaction is carried out in thepresence of hydrogen and/or synthesis gas.
 19. The process of claim 13wherein the reaction is a vapor phase reaction.